Well-controlled reversible addition-fragmentation chain transfer radical polymerisation under ultraviolet radiation at ambient temperature.

Controlled reversible addition-fragmentation chain transfer radical polymerisation of methyl acrylate was carried out under long-wave (lambda > or = 365 nm) ultraviolet radiation using an acylphosphine oxide as a photoinitiator at ambient temperature; the polymerisation shows a "living" character at high conversions of polymerisation and leads to well-defined polymers with narrow polydispersities (Mw/Mn < 1.1).